We plan to investigate the autonomic control of cardiovasculature changes using power spectral analysis of heart rate and blood pressure variability in five groups of women: 1) non-pregnant, normotensive women; 2) 16-18 week gestation, normotensive pregnant women; 3) 28-32 week gestation, normotensive pregnant women; 4) 37-40 week gestation, normotensive pregnant women; and 5) pre-eclamptic pregnant women at any gestational age.